I'm tryig to write a program to receive multicast packets. I running

I have create my socket, bound to the address and joined the multicast
group I wish to receive on (

This works fine when the packets being send have a source address of and a destination of

However when the packet is sent out with source & destination address of then the packet is getting dropped by the kernel. What do I
have to configure so that I can receive multicast packets that have been
sent with a multicast source address?